United States of America
Enviromental Issues Country Study
Website created by: Skye Henderson
Population Pyramid
A population pyramid is an analysis and visual representation of the distribution of different age groups in a population. The population is an effective way to demonstrate spikes or decreases in population growth in one period of time. For example, it is clear that the late 50 year olds and 60 year olds have a larger population than the late 30 year olds do. Why is this? Those who are in their 50's and 60's now were born in the baby boom that took place in the between the late 1940's and the early 1960's. It is also shown that the population growth has be relatively steady for the past years. There is no significant increase or decrease in the population of 15-19 year olds to the 0-4 year olds. Since the population pyramid shows total population growth and is not limited to fertility rates, immigration must be taken into account. According to PRB, the U.S. has a total growth rate is .77%. Immigration rates are about .37% which is nearly as high as the fertility rate in the U.S. if immigration is taken out of the equation, the U.S.'s population pyramid would look very different. Keep in mind that the population pyramid does not distinguish the difference between the increase in natural births or in immigration. Therefore, it is impossible to distinguish when there is a large increase in fertility rates or in immigration. Likewise, the population pyramid can not show which age most immigrants are. But it is possible to infer why there may be larger age groups than others. As mentioned above, there is record of a time period in the 1950's and 1960's of an increase in fertility rates. But there seems to be an increase of 20-24 year olds in this population pyramid. It is possible that there was just an spike in fertility rates that year, but it is also very plausible that the increase in population in that age group is due to immigration. Many young people immigrate to the U.S. to look for jobs and have a better life for their future family. It would make sense for many 20 year olds to come to the U.S. for that reason due to the fact that early 20's tends to be a time when many begin to look for steady jobs.
Demographic Transition Model
The demographic transition model demonstrates the stages that most countries follow when transitioning between an economically developing country (or "LDC" less developed country) to a economically developed country (or "MDC more developed country). Stage 1 represents the first stages of a country. Both birth rates and death rates are very high. Death rates are extremely high due to lack of food, good health, sanitation, and in many cases, conflict between different civilizations, human genocides or civil wars. When death rates are high, this results in high birth rates. Women are forced to have more children for to do labor work and to make up for those who have died. This results in a low and static population. In stage 2, the mortality rates begin to drop quickly while birth remain similar to the ones in stage 1. Better medicine and health care is developed meaning that fewer people die from illness. Since birth rates are still extremely high but death rates are quickly lowering there is an imbalance which leads to a sharp increase in the population. Stage 3 results in a decrease of birth rates. Since the mortality rate have signifigantly decreased, women feel less pressured to have large amounts of children. Additionally, women begin to move up in social status, allowing them to work and have a place in the community other than a reproducer. Stage 4 represents where the U.S. would be. Since both birth and death rates are low, the population remains high but plateaus. There is good technology and large progress in medical advancement. In stage 5, the birth rates are extremely low and mortality rates are low. The total population begins to decrease because there are very few children that are being added to the population. Though not many countries have entered stage 5, some countries such as Japan, Estonia, and a few other Northern European countries are in the beginning of stage 5.
Population
The United States still has an ever growing population. Why is this? Birth rates are not very high, women average on approximately 2 children each. Meaning that each parent is being replaced by a child, which results in a steady population. The population is still growing quickly due to the rise in immigration. Immigration is adding up to 2.25 million people to the U.S. each year. When adding both immigration rates and birth rates together, it results in a constantly increasing population.
Source: http://www.indexmundi.com/graphs/population-pyramids/united-states-population-pyramid-2014.gif
How does population relate to energy and climate change?
Why is population included on a website focusing on energy use and climate change? Population is actually a huge factor in the environmental issues that are being discussed. With a growing population, there is a higher demand for energy. More and more people are in constant need for energy, most of which is powered by fossil fuels. Fossil fuels are cheap and a easy short term solution to power our every growing country and world. Since there are more people using fossil fuels there is an increase in emissions that are released into the atmosphere. To sustain our growing population there needs to be cleaner energy sources that can still provide the immense amounts of energy we use each day. The increased demand for energy is not only because of the increasing population, but as the population increases and as more countries become more developed, the accessibility to energy increases. As developing countries begin to move towards becoming a developed country, the technology to use more energy is more available. The problem is, even if the resources tha we rely on are accessible does not mean that they will be accessible in the future. Our earth can not sustain the entire global population using the amount of energy that the U.S. uses today. On Global Footprint Network, they analyse your lifestyle and tell you how many Earths you would need to sustain the global population if they lived the same lifestyle as you. Here is he link to learn more: http://www.footprintnetwork.org/en/index.php/GFN/page/calculators/
This graph shows the sharp increase in both population and the total worldwide energy use over time. The red line represents the total energy and the blue line represents the total global population. It is clear that the levels of total energy consumption directly mirror the change in population. When the population rises, so does the total energy consumption. To learn more about energy use specifically in the U.S., go to the "Energy Use" page.